[GEM-dev] gem color bug

marius schebella marius.schebella at gmail.com
Tue Oct 30 04:05:10 CET 2007


hi chris,

chris clepper wrote:
> On 10/29/07, marius schebella <marius.schebella at gmail.com> wrote:
>>
>> I did not know that for coloring I do not need pix_alpha. sorry. so with
>> pix_rgba and color I can color all white pixels. nice.
>  
> I don't think pix_rgba is needed either.  On OSX any image file with a
> working alpha can be directly uploaded to the GPU and the alpha should
> work.  Also, Animation and None codec movie files will do the same.

I was only using black/white images and wanted the black part to be 
replaced by background. if I don't use pix_rgba, then I get a blue square.

> otoh, the real bug seems to be in pix_alpha. it does not replace black
>> pixels with alpha, but with blue... (?)
> 
> pix_alpha makes a fake alpha channel from averaging the R G B channels.
> This is not the right object to use if the image already has a pre-computed
> alpha channel.  It is possible that there is a bug in pix_alpha on Intel
> though.

why do you say "fake"?
and I don't have a pre-computed alpha channel. (I am using a black and 
white jpeg)
marius.




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